title: Ionic strength-dependent conformations of a ubiquitin-like small archaeal modifier protein (SAMP1) from Haloferax volcanii.
abstract: Eukaryotic ubiquitin and ubiquitin-like systems play crucial roles in various cellular biological processes. In this work, we determined the solution structure of SAMP1 from Haloferax volcanii by NMR spectroscopy. Under low ionic conditions, SAMP1 presented two distinct conformations, one folded β-grasp and the other disordered. Interestingly, SAMP1 underwent a conformational conversion from disorder to order with ion concentration increasing, indicating that the ordered conformation is the functional form of SAMP1 under the physiological condition of H. volcanii. Furthermore, SAMP1 could interact with proteasome-activating nucleotidase B, supposing a potential role of SAMP1 in the protein degradation pathway mediated by proteasome.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Science, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Kaiqin
authors.initials: K
authors.lastname: Ye
authors.forename: Shanhui
authors.initials: S
authors.lastname: Liao
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Kai
authors.initials: K
authors.lastname: Fan
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.forename: Jiahai
authors.initials: J
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Tu
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000187:drug effects; D019622:Haloferax volcanii / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009994:Osmolar Concentration; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D019843:Archaeal Proteins; D025801:Ubiquitin; D012965:Sodium Chloride; D046988:Proteasome Endopeptidase Complex
keywords: Haloferax volcanii; NMR; SAMP1; protein folding; ubiquitin-like protein